U-boats
-1
Section::::History.:20th century.:World War I.

Submarine
28825
U-boats
-1
Section::::Course of the war.:Western Europe (1940–41).

World War II
32927
U-boats
-1
Section::::Abstract.
U-boat
31888
U-Boats
U boats
Uboat
U boat
Unterseeboot
Unterseeboot
-1
Section::::Abstract.
U-boat
31888
U-Boot
U-Boot
-1
Section::::Abstract.
U-boat
31888
Eiserne Särge
German submarine
German submarine
-1
Section::::Course of the war.:Allies gain momentum (1943–44).

World War II
32927
German submarine
-1
Section::::Abstract.
U-boat
31888
U Boat
German submarines
German submarines
-1
Section::::Impact.:Advances in technology and warfare.

World War II
32927
German submarines
-1
Section::::Abstract.
U-boat
31888
U boot
U-boat
-1
Section::::History.:20th century.:World War I.

Submarine
28825
U-boat
-1
Section::::Course of the war.:War breaks out in Europe (1939–40).

World War II
32927
U-boat
-1
Section::::Abstract.
U-boat
31888
German U-boat
German U-boat
-1
Section::::World War I (1914–1918).

U-boat
31888
U-Boat
U-Boat
-1
Section::::World War II (1939–1945).:U-boat developments.

U-boat
31888
German U-boats
German U-boats
-1
Section::::World War I (1914–1918).

U-boat
31888
uboat
german submarine
german submarines
u boats
unterseeboot
u boat
u boot
german u boat
eiserne särge
german u boats